Simultaneous Removal of Phenol and Nitrate in an Anaerobic Bioreactor

• Published in: Journal of environmental engineering (New York, N.Y.) N.Y.), 2006-09, Vol.132 (9), p.1073-1077
• Main Authors: Zhu, Jian-Hang, Lin, Jin-Ping, Zhang, Bao, Yan, Xi-Luan, Peng, Zan-Guo
• Format: Article
• Language: English
• ISSN: 0733-9372
• DOI: 10.1061/(cE)0733-9372(2006)132:9(1073)..

Phenol and nitrate are two major pollutants simultaneously occurring in several industrial wastewaters. In this study, a 110-day gradual enrichment of an anaerobic culture has been carried out at 25DGC in an anaerobic bioreactor for continuously treating a synthetic wastewater containing 600 mg/L phenol and 430 mg/L NO-3N. The results showed that the enriched culture can utilize phenol as a sole electron donor and nitrate as a sole electron acceptor. At the end of the enrichment (on Day 110), 93.3% of phenol and 98.0% of NO3N were simultaneously removed at a hydraulic retention time of 20.25 h in the anaerobic bioreactor. The removal of 1 g NO3N required about 3.19 g chemical oxygen demand as the electron donor. Batch tests further revealed that cresol, nitrophenol, and monochlorinated phenol (MCP) could exert detrimental influences on the treatment abilities of the enriched culture. However, the inhibitory effects of cresol were impermanent, as compared to those of nitrophenol and MCP. In order to operate the anaerobic bioreactor steadily, high concentrations of cresol should be diluted before being fed while the existence of nitrophenol and MCP in the bioreactor should be avoided.